Port Groups

Each module has four groups of one or more ports in port groups that share common resources, such as bandwidth and buffer credits. The following table shows the port groups for the Generation 2 Fibre Channel switches and modules.

Port groups are defined by the hardware and consist of sequential ports. For example, ports 1 through 12, ports 13 through 24, ports 25 through 36, and ports 37 through 48 are the port groups on the 48-port 4-Gbps Fibre Channel switching modules.

Port Speed Mode

The following table shows the port speeds allowed on each Generation 2 switching module.

Table 5-3 Configurable Port Speeds on Generation 2 Switching Modules

Module

Port Speed Modes

Default Configuration

48-port 4-Gbps

Auto, auto (max 2 Gbps), 1, 2, 4

Auto, shared

24-port 4-Gbps

Auto, auto max 2000 (2 Gbps), 1, 2, 4

Auto, shared

12-port 4-Gbps

Auto, auto max 2000 (2 Gbps), 1, 2, 4

Auto, dedicated

4-port 10-Gbps

Auto1

Auto, dedicated

1 4-port 10-Gbps can be configured as auto mode, but only supports 10-Gbps connections.

Dynamic Bandwidth Management

Table 5-4 Bandwidth Reserved for Dedicated Mode

Port Speed

Bandwidth Reserved per Port

Auto / 4 Gbps

4 Gbps

Auto max 2000 / 2 Gbps

2 Gbps

1 Gbps

1 Gbps

101

10 Gbps

1 Available only on the 4-port 10-Gbps switching module.

Table 5-5 shows the bandwidth reserved based on port speed for ports in shared mode.

Table 5-5 Bandwidth Reserved for Shared Mode

Module Type

Port Speed

Bandwidth Reserved

24-port 4-Gbps

Auto / 4 Gbps

1 Gbps

Auto max 2000 / 2 Gbps

0.5 Gbps

1 Gbps

0.25 Gbps

48-port 4-Gbps

Auto / 4 Gbps

0.8 Gbps

Auto max 2000 / 2 Gbps

0.4 Gbps

1 Gbps

0.2 Gbps

Note:

When migrating a host only supporting up to 2-Gbps traffic to the 4-Gbps switching modules, use autosensing with 2-Gbps maximum bandwidth.

Note:

The 4-port 10-Gbps switching module only supports 10-Gbps links.

Out-of-Service Interfaces

You can take interfaces out of service to release shared resources that are needed for dedicated bandwidth. This feature is especially useful for the 48-port 4-Gbps switching modules. When an interface is taken out of service, all shared resources are released and made available to the other interface in the port group or module.

Caution:

If you need to bring an interface back into service, you might disrupt traffic if you need to release shared resources from other interfaces.

Port Index Availability

Each chassis in the Cisco MDS 9000 Series has a hardware-based maximum port availability based on internally assigned port indexes. When the maximum number of port indexes is reached in a chassis, any modules remaining or added to the chassis will not boot up. The number of physical ports on a Fibre Channel module is equal to its number of port indexes. However, for Gigabit Ethernet modules (IPS-8, IPS-4, and MPS-14/2), one physical port is equal to four port indexes (one port index for iSCSI and three port indexes for FC IP tunnels). Table 5-6 lists the physical ports and port indexes (virtual ports) allocated per Cisco MDS 9000 module.

Using any combination of modules that include a Generation 1 module or a Supervisor-1 module limits the port index availability to 252 on all Cisco MDS 9500 Series directors. Generation 1 modules also require contiguous port indexes where the system assigns a block of port index numbers contiguously starting from the first port index reserved for the slot that the module is inserted in (See Table 5-7). Even though there may be enough port indexes available for a Generation 1 module, the module may not boot up because the available port indexes are not in a contiguous range or the contiguous block does not start at the first port index for a given slot.

Example 5-1 shows a case with a Supervisor-1 module, where a 48-port Generation 2 module borrowed port indexes from the first slot. Slot 1 still has 16 port indexes available, but the full 32 indexes are no longer available (28-31 are used by the module in slot 4). This means that no Generation 1 module except a 16-port Fibre Channel switching module can be inserted into slot 1 because some of the port indexes for the slot are already in use.

If you use any combination of modules that include a Generation 1 module and a Supervisor-2 module the port index availability is limitedt to 252 on all Cisco MDS 9500 Series directors. The Generation 1 modules can use any contiguous block of port indexes that start on the first port index reserved for any slot in the range 0-252.

Using any combination of only Generation 2 with a Supervisor-2 module allows a maximum of 528 (with an architectural limit of 1020) port indexes on all Cisco MDS 9500 Series directors. Generation 2 modules do not need contiguous port indexes. Generation 2 modules use the available indexes in the slot that it is installed and then borrow available indexes from the supervisors. If the module requires more indexes, it starts borrowing available indexes from slot 1 of the chassis until it has the number of port indexes necessary.

Note:

Use the purge module CLI command to free up reserved port indexes after you remove a module.

Table 5-7 Port Index Requirements

Supervisor

Module

Port Index Requirements

Supervisor-1

Generation 1

Indexes must:

•Be contiguous.

•In the range assigned to the given slot.

•Start with the lowest value assigned to that slot.1 2

•Have no port indexes above 256 allocated to any other operational modules.

Maximum 252 assignable port indexes available.

Generation 2

Indexes can be any available number in the range 0 to 252.

Supervisor-2

Generation 1

Indexes must:

•Be contiguous.

•Start with the lowest value assigned to any slot.2.

•Have no port indexes above 256 allocated to any other operational modules.

Maximum 252 assignable port indexes available.

Generation 2

Indexes can be any available number in the range 0 to 1020 if all modules are Generation 2 modules. Otherwise, indexes can be any available number in the range 0 to 252.

1 See the Allowed Ranges column in Example 5-1 for the port indexes assigned to each slot for Generation 1 modules.

Combining Modules and Supervisors

All the existing Generation 1 and Generation 2 switching modules are supported by Cisco MDS SAN-OS Release 3.0(1) and later. However, there are limitations to consider when combining the various modules and supervisors in the Cisco MDS 9500 Series platform chassis.

You can combine Generation 1 and Generation 2 switching modules with either Supervisor-1 modules or Supervisor-2 modules. However, combining switching modules and supervisor modules has the following limitations:

Use a Supervisor-2 module and all Generation 2 modules in a chassis to get up to 1020 port indexes.

Use the show port index-allocation CLI command to determine available port index values before inserting new modules in a chassis if you have a mix of Generation 1 and Generation 2 modules.

Use only Supervisor-2 modules on a Cisco MDS 9513 director.

Note:

You cannot downgrade from a Supervisor-2 module to a Supervisor-1 module.

Verify that no Supervisor-1 modules are used in a Generation 2 switch.

Use the show interface transceiver CLI command to view enhanced diagnostics on the X2 transceivers for Generation 2 modules. This is supported on 4-Gbps and 10-Gbps ports. Use these diagnostics to isolate physical layer problems, such as contact problems, major failures within SFPs, or abnormal error rates associated with excessive optical attenuation. The diagnostic information includes temperature, voltage and current, transmit power level, and receive power level.

Generation 1 and Generation 2 Issues

Module Does Not Come Online

Symptom Module does not come online.

Table 5-8 Module Does Not Come Online

Symptom

Possible Cause

Solution

Module does not come online.

Not enough port indexes are available.

See the "Verifying Port Index Allocation Using Device Manager" section or the "Verifying Port Index Allocation Using the CLI" section. If the switch has Generation 1 modules inserted, upgrade to all Generation 2 modules to gain higher total port index availability.

Available port indexes are non-contiguous.

See the "Verifying Port Index Allocation Using Device Manager" section or the "Verifying Port Index Allocation Using the CLI" section.

Not enough power is available in the chassis.

Use the show environment CLI command to determine if you have enough available power for the module. Upgrade your power supply, if necessary.

In this example, there is not enough available shared bandwidth in Port-Group 1 to switch any more ports to 4 Gbps dedicated mode.

2. Free bandwidth for the port that you want to place in dedicated mode by performing one of these tasks:

Use the out-of-service command in interface mode to put one or more ports in out- of-service mode to free more resources.

Use the swtichport speed command on one or more ports to change the port speed to a lower port speed. See the "Dynamic Bandwidth Management" section for the minimum bandwidth requirements for port rate modes and port speeds.

Cannot Enable a Port

Symptom Cannot enable a port.

Table 5-10 Cannot Enable a Port

Symptom

Possible Cause

Solution

Cannot enable a port.

Port is out of service.

In Device Manager, right-click the port and select Configure to see if the port is out of service.

Using the CLI, use the show interface brief command to see if the port is out of service.

See the "Verifying Bandwidth Utilization in a Port Group Using Device Manager" section or the "Verifying Bandwidth Utilization in a Port Group Using the CLI" section to free up enough port resources to bring the port in service.

Not enough bandwidth is available in the port group.

See the "Verifying Bandwidth Utilization in a Port Group Using Device Manager" section or the "Verifying Bandwidth Utilization in a Port Group Using the CLI" section.

Cannot Upgrade Supervisor System Image

Symptom Cannot upgrade supervisor system image.

Table 5-11 Cannot Upgrade Supervisor System Image

Symptom

Possible Cause

Solution

Cannot upgrade supervisor system image.

Wrong Cisco SAN-OS image type.

Use the appropriate Cisco SAN-OS image for your supervisor. See the "Selecting the Correct Software Images" section. In Device Manager, choose Physical > Modules to find the supervisor type.

Or use the show module CLI command to determine the supervisor type.

Selecting the Correct Software Images

The Supervisor-1 and Supervisor-2 modules supported by Cisco MDS 9100, 9200, and 9500 Series switches require different system and kickstart images. You can determine which images to use on your switch by the naming conventions shown in table 5-12 below.